FIG. 12 is a perspective view of conventional physical quantity sensor 500 disclosed in PTL 1. Vibrator 1 is accommodated in housing 2. Temperature sensor 3 is accommodated in housing 2 for sensing a temperature around vibrator 1. Peltier element 4 is disposed on an upper surface of housing 2. Temperature controller 5 controls a direction and an amount of an electric current flowing through Peltier element 4 so that a temperature in housing 2 can be controlled at a constant level.
An operation of conventional physical quantity sensor 500 will be described below. Upon having an alternating-current (AC) voltage applied, vibrator 1 vibrates 1 in a direction of a Y-axis symmetrically. Vibrator 1 is rotated at an angular velocity ω about a Z-axis while vibrator 1 vibrates, and then, a Coriolis force is produced on vibrator 1. An electric charge generated on vibrator 1 due to the Coriolis force is converted into an output voltage to detect the angular velocity.
When an ambient temperature around physical amount sensor 500 changes, a change in the output signal due to the temperature change can be prevented by the following mechanism: the temperature in housing 2 is sensed with temperature sensor 3, the direction and the amount of the electric current applied to Peltier element 4 are controlled with temperature controller 5, thereby the temperature in housing 2 is controlled at a predetermined level. Conventional physical quantity sensor 500, however, includes a large number of components and has a large size accordingly.